This invention relates generally to methods and systems for detecting chemical or biological substances by employing a light scattering probe and a chemical sensor.
Light scattering methods such as Raman spectroscopy are known sensitive technique for detecting chemicals and biological agents. Due to technical difficulties, conventional Raman scattering sensors have so far limited applications. A major limitation in Raman spectroscopy is that the Raman scattering signals from trace chemicals tend to be very weak. Many attempts have been made to increase Raman scattering intensity. Such efforts, however, have not been able to deliver Raman spectroscopy-based detectors for practical and economical applications, despite urgent needs in many fields of applications such as antiterrorism, forensic analysis, disease diagnosis and prevention, industrial process monitoring, environmental cleaning up and monitoring, food inspection, anti-counterfeiting, and drug quality control.
Therefore, a need exists to provide effective and practical spectroscopy-based detectors for detecting trace amount of chemical or biological substances.